Wind turbines are mainly divided into two major systems, “lift-type” and “resistance-type”. The lift-type wind turbines are commonly located at open spaces, such as seaside. They are quite huge and named after their huge lift blades. However, since nature wind is non-directional turbulent flow. The wind turbine must face the wind in the windward side so that the wind can push the lift blades. Hence, there is a herd mechanism on the structure so as to move the lift blades to the windward direction along with the wind. However, corresponding mechanism of the blades and the generator become more complex. Prices are higher. Maintenance costs also go up.
Another type, the “resistance-type”, wind turbines have blades similar to the sailing. However, according to practical experiences, it will generate turbulent flows when running and further cause low efficiency. Furthermore, when such generating equipment meets the wind, the blades facing straight to the wind rotate clockwise. Other blades meeting the wind in back rotate counter-clockwise. Such conflict direction of rotation will lead to “braking” phenomenon and affect power generation efficiency.
Whether it is “lift-type” or “resistance-type”, the wind turbines are required to produce electricity by rotating blades. Wind turbines need to track the wind direction. The cables connecting the generator should be able to continuously twist forward and reverse with the wind. Although general cables used in the wind turbine have a certain degree of resistance to torsion, when the generator rotates over and over again in long-term, it reverses the cables and finally will cause fracture of the shield lines in the cables. Hence, it is desired for the relevant industry to research and develop a method to avoid the shield lines from breaking while the cables reverse.